1. Field of the Invention
The disclosure relates to a vibratory downhole rotary apparatus and a method for use of the apparatus. Generally, but in no way limiting, the downhole rotary apparatus can include a metallic stator.
2. Brief Description of Related Art
Conventional oil and gas drilling involves the rotation of a drill string at the surface which rotates a drill bit mounted to the bottom of the drill string. In other drilling operations, a motor may be used to rotate the drill bit. In these situations it can be more difficult to advance the drill bit in a hydrocarbon formation. These motors are also used with coiled tubing and jointed pipe in completions and other operations. These motors typically include rotors disposed within elastomeric stators. Elastomeric stators can have deficiencies when it comes to breaking down and handling the operating conditions imparted upon them during downhole operations. Downhole motors coupled to conventional mechanical valves are used in some vibratory tools. The mechanical valves used in these tools, which vary the flow area through a flow aperture require substantial torque for operation. Currently, motor with elastomeric stators are the only suitable downhole motor type which can produce enough torque to operate these mechanical valves. This high torque requirement dictates that the rotors and stators must have substantial length in order to provide the required internal torque to operate the tool.
To this end, a need exists for a vibratory downhole rotary apparatus that can operate with a low internal torque and is constructed of materials more suited to the operating conditions and wear and tear from use.